The present invention generally relates to latch comparators and, more particularly, to a latch comparator that eliminates kickback noise.
Comparators are used in analog circuits and analog-to-digital (ADC) circuits. FIG. 1 shows a latch comparator 100 that includes a preamplifier 102 and a latch 104. The preamplifier 102 receives a differential input signal in_p, in_m and generates a pre-amplified differential signal that is provided to the latch 104. The latch 104 compares the pre-amplified signals and generates a latched differential signal out_p and out_m. The latch 104 also receives a latch signal at an enable terminal thereof. The latch signal configures the latch 104 to operate in a reset mode or a latch mode. In the reset mode, the output signals out_p and out_m are reset, and in the latch mode, the latch 104 functions as a normal latch circuit.
A main concern of the latch comparator 100 is the kickback effect, where the operation of the latch 104 impacts the operation of the preamplifier 102 such that the output of the preamplifier 102 may be affected, which can result in incorrect values being latched by the latch 104.
Accordingly, it would be advantageous to have a latch comparator that handles kickback effects.